Operator-protecting spray booth



SePf- 30, l941- J. F. ROCHE, JR., ET'AL 2,257,516

OPERATOR PROTECTING SPRAY BOTH Filed March l, 1938 -2 sheets-sheet 2 Patented 30, 1941 "John F. anche, Jr., oak Para, ana

lll., assisnors to Bink.

shire, Chicago,

NT Aoiuucii ma nur Manufacturing Company, Chicago, lll., a corpora- `tion or Delaware Application Marchi, nass.` semi Ne. 193,320 s claims. (cit iii-so) Our invention relates to booths within which work is performed and out of which airis drawn to Icarry o1! fumes, v I so a's to prevent such injurious materials from being breathed by the workman. its general objects being those of providingbooths of this class which will effectively protect. the spray device operator or other workman from breathing siliceous particles or the like airvitlated byproducts of the working process,

without requiring an undesirably large volume of air to be moved through the booth for that purpose.v and without hampering the workman. f coating of a comparatively small Y object itl is commonly customary to have the In the spray l spray gun operator stand either in front of or inside the spray' booth within which the object is supported, with the operator iacing the rear wall oi the booth, and with the spray-receiving such vitreous particles toward the head ot the operator. Owing to the just recited conditions,4

the sprayer of a vitreous enamel is apt to breathe air laden suiliciently with ceramic dustl to causesilicosis. Respiratory ailments may likewise oc- -cur during`the spraying oi' othenmaterialsfy or during turningorl grindingA operations which in- Y voive the detaching of particles adapted to vitiate the air in the'boo In one of its maior objects, our inventionaims to overcome the just recited serious diiliculties which is to draw the fumes or other waste particles toward the fume-material-colleoting -rear object disposed between the operator and the rear wall or the booth: ,l It Vlikewise is customary to have the part of therear wall toward which the fumes of the coating material the spray appliance terminate atan elevation lower than that of the object, and "to provide means for drawing air rearwardly from the booth under the lower edge of the said rear wall part andtherearter past fume-material precipitating means to an exhaust nue.

In practice, the air draft through such a booth has been adequate, with, the booth closed at vits top and open at its front.- for carrying the major part lofthe fumes oi homogeneous coating materials away from the spray gun operator and out of the booth. v

However, diinculties have been encountered when the sprayed material is not homogeneous, and particularly when this material, consists of solid particles much lower speciilc gravity. a sbcalled vitreous enamelground vitreous particles suspended in a speedily vaporlzable liquid. With such a material, the velocity o! the projected spray imparts a higher momentum to the vitreous particles than it does to the particles of the liquid carrier, so4 that the heavier vitreous particles not onlytend to flick'v out of the liquid particles but also may rebound Since at least a part or thespr'ayed object is usuallydisposed at lower elevation than` the outlet will ilow mainly shoulders; so

are directed by i acteristics so that suspended in 'a carrying liquid of as for example with.

beneilcial characteris'ti consistingl of ilneiy.

in various directions from the object which being sprayed.

the rebound o! 55 booth head g that the latter can and unvitiated air.' to arrange the air -tiow through the booth so wall and out of the booth will ilrst pass the 'that the Just mentioned part of the air will move downwardly in front o! the operators head.' for downwardly deilecting fumes or other particles which may rebound toward the operator's head. Furthermore. our invention-aims to construct operator-.housing booths of the just'recited chari some oi the additionalair, needed for'carryingfumes or detached particles toward the rear wall o! the booth and thereafter past the usual washing provisions to a ilue,\wil1 also direct the said downwardly moving `%irV rearwardly, after the laat named part of the air has moved downwardly below the head and chest Voi the operator. In addition, our invention aims to construct such booths so that the previously recited air movements can be 'obtained without subjecting the operator to any objectional draft.

In a still further object, our invention aims to provide booth constructions of the just recited constructed sothat the desired `operation of.E the workman can bev upon objects which are successively moved through the boothby a conveyor or 'e like. i

Illustrative oi' the manner in which we accomi plish theabove listed seneral objects, as well asA other 'more detailed objects:

Fig. l is a perspective view ot a booth embodyins ourinvex'itionl and designed for housing and protecting ,an operator while working on a rotatable object as for example during afturning .or

grinding operation.

Fig. 2 Ais `an enlargedl vertical sectionftakenr constructing booths so thats part of the air and upper body portion of the operator, so. e continuously breathe fresh Moreover, our invention aims now of the part of the fresh airwhich is to be breathed by the operator.

Fig. 3 is a-plan view of the booth of Figs. 1 and 3, drawn on a scale intermediate of those figures,

' with arrow lines indicating the directions in 5 which additional airenters -through-slots inthe door-like front plate and through lthe frontal booth opening adjacent to the free edge of that plate. f

Fig. 4 is a perspective view of another embodij ment'of our invention, 4constructed for ,allowing the work pieces to be moved through the booth by aconveyor.

Fig. 5 is an enlarged vertical section.. taken t along the line 5-5 of Fig. '4 and including porla tions of a conveyor, a work-piece suspended from the conveyor, and a dotted .line picturiig 'of -a workman positioned for spraying this work-piece. Fig. 6 is an enlargement of a portion of Fig. 2,

`showing the adjustable supporting of the air deiiector which underhangs the upper air inlet.

In the embodiment of Figs. 1 to 3, the main' Vtively wideopening O. Extending from onev riser edge of this opening (afterthe manner of a partially bpen door) is a shield plateP which w extends forwardly at la desirably sharply acute angle to the planeof the booth front F, leaving sufficient space adjacent to its free riser edge for the entry of the operator and the transporting of work-pieces and tools into the booth. This 35 shield plate yis provided. desirably only near the riser edge at which itis connected to an adjacent part of the box-like housing, with air ports, such as the slots j2 in Figs. 1 to 3, the upper air inlet I also being nearerto the same riser side o lof the housing. l

The rear wall W-has .an opening- 3 intermediateof its height, desirably in form of a slot ex-Mv tending across the entire interior width of a taller rear compartment C", the bottom portion of 5 which rearcompartment stores water l for collecting otherwise wasted material. Extending rearwardlydownward from. the upper edge of the opening Band thereafter downwardly, and

.e freely spaced from the rear wall of the said compartment is a baille 5 which has ,its `lower l `edge at a higher elevation v than the level of the saidwater.

' A direct horizontal ow of air,"fumes and the 4like rearwardly fro'm the booth proper to the! 55 saidconnecting opening l is preventedv by the usual bailiing, as by two fume-material collecting baiiles b and b? consecutively spaced forwardly from the rear booth wall W and provided with apertures w h preferably are relatively staggered in-thetwo bailles. These baiiies preferably have their lowjer edges -at an elevation intermedij lowing' a work` piece 2i to move-,freely through ate that of the door 6 of the booth proper and -of the lower edge 31 of thesaid connecting opening 8, andjshe baiiies are freely underhuxg by an both the said defiector and top. so that the dflector can be adjusted a's to the distance of its forward end from the`front of the booth.

Duringf-the use of our just described two-compartment booth, as for example for some lfinishing operation on a cylindrical work piece 9 supported by astand l0, the workman il stands between the said stand and the front of the booth, When the usual suction fan I6 is running for drawing air upwardly past the usual water sprays i3 and the eliminator i4, and for ejecting that air through the flue l2, the suction draws air out of thaty booth proper (or forward compartment) through the connecting opening 3,

The resulting rearward draft then draws air rearwardly into the workcompartment through the opening at the free edge of the shield plate P and the slots in that plate, and also downwardlythrough the upper inlet I. However, the sloping defiector 1 below the inlet guides the admitted air so that this flows downwardly in front of the operators head and shoulders, after whichl air admitted through the ,said slots aids in curving the flow rearwardly (as alongthe arrow'lines I5of Fig, 2) past the workpiece 9 and toward-the rear opening 3. Moreover, some of the slots 2 in the doorlike shield P may extend higher than the top of the workmans Jhead,`

thereby causing some air also to be drawn rearwardly past and even above his head. Consei quently, owing to the joint result of the upperyair inlet, the air-guiding baille 1 and the slots in:

the said shield, the air Vbreathed by the workman is entirely free of the injurious particles which may result from the working operation.

By disposing the 'upper inlet I nearer to the booth side-atwhich the frontal shield is connected to thev yremainder of the booth than to the opposite booth side, I' also allow the maior part of they frontally admitted airto enter (asalon'g the arrow lines i1 of Fig. 3) without subjecting theoperator to an undesirable draft. Moreover, as will readily be -understood without further picturing, the frontal shield platel may be `hinged to the remainder of the booth, thereby permitting an adjustment of theair admitted pastthe vfree/riser edge tothe door. J YJ.

However, while we have heretofore described an em partment, weprovide the sides S o f this same compartment withl counterpart and enlarged openings I9 (Figs. 4 and 5) through the upper portion of which openings a conveyertrack A2 0 extends.' Each such: opening is shaped for alit's'main part, and also allowing clearance Afor work-suspending means 22.

diment of our invention which has provr en both convenient and effective for accgAmplishing our recited objects,v many changes"may be; made without departing either from the spirit inclined battle l5 which is supported by and slopes Then we desirably 'a l forwardly downwardly from the rear wallW Q1 the tlrougha chute 23 which slopes downward forbooth proper y j 1 i g wadly for directing the air downwardly bey A direct downward flow of ai; mi 'theV booth Atween the operator Il and the work-piece, with through the inlet I in the top ofthe booth islikethe rear wall 23* corresponding tothe air dewise prevented by an air deiiector 1 which unf eciior l in Figs.-1 and 2.' Also. instead of the derhangs the upper air inlet I in the booth top Y flODtl air admitting provisions of Fiss. 1 We T and slopes forwardly downward'this deiiector employ a front 2.4 which is `losed except forn being desirably. fastened to the said top (as in a horizontal yslot llhwhichl desirably extends sub'- Fig. 6) by bolts 8 extending through slotsv in 75 stantially across the said front and at an ele-fl t the breathable air l ,asasre s 3 vatios apiiroximating that ci the booth outlet sai-scies cui from the work mic the chamber opening `i1. g f will be caught by the downwardly flowing stream In addition, we dcsirably provide asecond air in front of the work location and diverted into inlet 2s. for adm tting air downwardly behind the the rearwardly lowing stream. rear wall 23a of the said chute, and provide a hor- 5 3. A booth for housing a pleceof'work at which izontal baille plate 2t extending rearwardly from particles of material will be cast into adjacent the lower end of the said chute wall Il* to prespace with high momentum `during work operavent the admitted air from flowing directly downcomprising side walls, iront and rear walls ward upon the work-piece. Withthe Just named having air inlet and outlet means respectively, bame thus disposed, the air admitted through the lo so arranged that a stream of air may travel rearbooth top behind the said air chute is drawn wardly through the booth past a predetermined downwardly rearward (as along the arrow lines work location. a top having an opening for entry Il) through the suction produced by the flue fan, of air into the booth, means for causing a flow and this carries fumes or the like with it, of air through said booth from the front to rear while the operator breathes only the uncontamthereof and inwardly through said top opening, inated air which enters through the chute Il an air guide means below said top opening so 1oand thereafter moves along the arrow lines il. cated as to extend toward the front of the booth Thus the construction o! each of our illustrated over the said work location and invsuch manner embodiments readily guards the operator against as to direct a downwardly flowing stream of air respiratory troubles, `such as heretofore had preinto the space between the front wall and the vented a more extensive use of certain materials. e

Moreover, by suitably proportioning the various air inlet provisions of either embodiment to the general dimensions of the booths, the characteristics of the materials which otherwise would cause respiratory ailments, and the rate at which these materials are to be consumed. we can also eifect the desired. safeguarding ofthe operators health without moving so large a quantity of air as to increase the operating costs unduly because of the power required for moving the til'- We claim as our invention: Y

1. A booth for housing a piece of work at which particles of material will be cast into adjacent space withA high momentum during'work operaso arranged that a Y rearwardly through lthe chamber past a predetermined work location, a top having en opening opening being located walls than to the other.

nearer to one of said side the front wall of the booth to'rear thereof and downwardly through said top opening, and guide andthe iront wall at a position adiacent'to said work location, whereby particles cast from the work into the adjacent space will be caught by the downwardly flowing stream in front of thefront and rear walls means respectively,

t a shield extending iiow of air through the booth from front to rear v oi the latter and ing, and a guide wall said booth from the ing and forwardly of the front edge of the latter to a position above said work location. said guide wallbeingsopositionedastodirectadownstream of air into the space between the work location andthe front wall at a inwardly through saidA top openextending downwardly into A' rear edgeof said top openposition adjacent to'said work location. whereby 7s tions, comprising air inlet `'so arranged that near said one of said side walls for assisting in diverting the downwardly flowing stream of air, the

inlet in the front of said booth being located nearer to the other oi said side walls.

4. A booth for-housing a particles of material will be cast into adjacent space with high momentum during work operaside walls; front and rear walls wardly through l work location, a toprlfiavingan'opening for entry vof air into the th, means-for causing a ilow of air through said booth from the front to rear thereof and inwardly through said top opening, an air guide located as to extend toward the front of the booth over the said work location and in as to direct a downwardly flowing into .the space between the front wall and the work location but nearer to the latter, whereby particles cast from the work are intercepted by the downwardly flowing air stream and rearwardly flowing air stream, said an upright panel adjacent to of one side of the booth, and from the forward edge of the other side oi' the booth at an acute angle to the common plane of the having air ports only to the forward edge booth 5. A booth i'or housing a piece of work at which particles of material will be cast into adjacent space with high momentum during work operations, comprising side walls, frontend rear walls having air inlet and outlet means respectively,

in a part thereof adjacent of the other side of the booth lover the said work location, said air guide means below said top opening so such manner v stream of air directed said'two edges. the shield' wardly through worklocation. a wp having an openingtor entry 6. Abooth-'Ior housing a piece of work at which particles of material 'willbe cast into adjacent ,space with high momentum during work operations, comprising side walls, front and rear,` walls having air inlet and loutlet means a stream of air may travel rearthe booth past a predetermined so arranged that of air into the booth. means for causing a ow of air through said booth from the vfront to rear thereof and inwardly through said top opening, an air 4guide means below saidj'top opening `so located as to extend toward` the front of the from the work areintercepted respectively.

- manner as to directa 'booth over -the` said y downwardly flowing stream clair-into the space between the .work location but nearer to by particles'cast from the work are the latter, whererectediinto saidv Alet'fopening adjacent opening and rearwardly of said guide means, I' whereby said guide means to said 'iirst mentioned guides the air enterins'the booth through said land a substantially horizontal bame extending rearwardly' from the lower end of said yguide meansl for preventing the air entering through said auxiliary opening reaching said work location. Y

' y' JOHN F. ROCHE, Jn. MATT DARBYSHIRER work location' andfin Asuch' l the front wall and intercepted l by the downwardly ilo'wingair stream and diy rearwardly nowing air stream,v

auxiliary opening, 

